The current study aims to evaluate the effects of a novel, microenterprise randomized clinical trial intervention on HIV/STI incidence among female sex workers (FSWs) in Chennai, India. There has been a growing attention for the need to address structural factors in HIV prevention intervention research. The POWER (Promoting Opportunities for Women through Economic Empowerment) study is informed by psychological empowerment and asset theories. It is also informed by lessons learned from a randomized, pilot, feasibility study of FSWs (N=100) which taught us that women were extremely interested in learning tailoring skills and that involvement in the pilot was associated with reductions in the number of sex trade clients, an increase in licit income, and an overall increase in monthly income. This current study aims to determine the efficacy of a bag-making, tailoring microenterprise intervention compared to an equal attention control condition among FSWs (N=500) in Chennai at 6-, 12-, and 18-month follow-up on: reducing cumulative HIV/STI incidence (primary outcome) as well sexual risk behaviors (e.g., number of sexual partners and unprotected vaginal sex) (Aim 1);assessing if specified intrapersonal, interpersonal, and economic factors mediate the intervention's effect on the sexual risk behaviors (Aim 2);conducting economic evaluations to examine the intervention arm's cost, cost per HIV infection averted, and the break-even point at which point the intervention is cost saving (Aim 3);and exploring the effects of participation in the intervention arm on women's self-esteem, gender equity in their sexual relationships, and overall feeling about themselves and their household contribution (Aim 4). To achieve these aims, participants will be randomly assigned to the two arms and will be followed at 6, 12, and 18 months. Women will be recruited through targeted sampling from a range of street-based venues identified through existing data, observations, and ethnographic mapping conducted throughout data collection. The intervention will be comprised of two, individual, Project RESPECT, HIV prevention, pre- and post-test counseling sessions plus 100 hours of master tailoring training taught in small groups from experienced instructors. The equal-attention control arm will also be comprised of the two, individual, Project RESPECT sessions plus 100 hours of small group, English lessons taught by adult education teachers. All participants will be HIV/STI tested at each visit. While tailoring is distinct from sexual risk reduction, we hypothesize that providing women HIV prevention tools combined with the empowering and transformative process of learning a marketable skill among peers, will lead to sustainable STI risk reduction. PUBLIC HEALTH RELEVANCE: The current study will examine the effects of a structural intervention on cumulative HIV/STI incidence among female sex workers, namely, an economic empowerment study. Ultimately, the evaluation will provide the cost effectiveness of such an intervention as well as the impact on HIV/STI incidence and risky behaviors.